What is the best treatment approach for suspected functional dyspepsia following a bout of gastroenteritis?

Management of Post-Infectious Functional Dyspepsia

You should first undergo non-invasive testing for Helicobacter pylori and receive eradication therapy if positive, followed by a trial of proton pump inhibitor therapy at the lowest effective dose if symptoms persist. 1

Understanding Your Condition

Your symptoms following gastroenteritis represent post-infectious functional dyspepsia, a recognized disorder of gut-brain interaction that occurs after acute gastroenteritis. 1 Research demonstrates that post-infectious functional dyspepsia involves increased mast cells and enterochromaffin cells in the gastric mucosa, with elevated release of histamine and serotonin contributing to your symptoms. 2 This is not a psychological condition but rather a physiological response to the infectious trigger. 1

Initial Diagnostic Steps

• Test for H. pylori infection using a validated non-invasive test (breath test or stool antigen test). 1, 3
• If you have overlapping bowel symptoms (diarrhea, constipation, bloating), request coeliac serology testing. 1
• Endoscopy is not routinely needed unless you are ≥55 years old with weight loss, or have other alarm features. 1

First-Line Treatment Algorithm

If H. pylori Positive:

• Receive eradication therapy immediately - this is the only treatment proven to change the natural history of functional dyspepsia. 1, 4
• Wait 4-8 weeks after successful eradication to assess symptom response. 1
• If symptoms persist after confirmed eradication, proceed to PPI therapy. 1

If H. pylori Negative:

• Start empirical acid suppression with a PPI at the lowest dose that controls symptoms (no dose-response relationship exists). 1
• Continue for 4-8 weeks initially. 5
• H2-receptor antagonists (like famotidine) are an alternative but less strongly supported. 1

Lifestyle Modifications:

• Begin regular aerobic exercise - this has a strong recommendation despite limited evidence quality. 1
• Avoid specific foods that trigger your symptoms, but do not adopt overly restrictive diets that could lead to malnutrition or disordered eating. 3, 6
• There is insufficient evidence to recommend low FODMAP or other specialized diets. 1

Second-Line Treatment (If First-Line Fails After 4-8 Weeks)

Tricyclic antidepressants are the evidence-based second-line therapy, particularly effective for epigastric pain. 1, 3

• Start amitriptyline 10 mg once daily at bedtime. 1
• Titrate slowly to a maximum of 30-50 mg once daily based on response. 1
• Explain clearly that this is used as a gut-brain neuromodulator, not for depression, to improve adherence. 1
• Counsel about side effects (dry mouth, drowsiness, constipation). 1

Prokinetic agents may be considered if available in your region, though efficacy varies and many are unavailable outside Asia/USA. 1

When to Seek Specialist Referral

Referral to gastroenterology is appropriate if: 1

• Symptoms remain severe or refractory after first-line treatments
• There is diagnostic uncertainty
• You develop new alarm features (weight loss, persistent vomiting, dysphagia)

Critical Pitfalls to Avoid

• Do not undergo routine gastric emptying studies or 24-hour pH monitoring - these are not indicated for typical functional dyspepsia symptoms. 1
• Avoid opioid medications for symptom management as they worsen outcomes. 3
• Do not pursue surgical interventions for functional dyspepsia. 3
• If you develop significant weight loss or food restriction, screening for eating disorders (including ARFID) is essential. 3

Management of Refractory Cases

If symptoms persist despite the above measures, you should be managed by a multidisciplinary team including your primary care physician, a dietitian, gastroenterologist, and potentially a psychologist. 1, 3 Combination therapies (such as TCA plus PPI) may be considered at this stage. 3